SAG-AFTRA President Ken Howard today called his opposition's sweeping agenda for change "empty promises" and "hollow rhetoric." In an email sent to the union's members, he said that the record of Membership First — the slate opposing his Unite for Strength candidates in next month’s election — "is one of conflict, division and, ultimately, failure." "This election is critical to your future as a performer and as a union member," Howard wrote. "There are those who want to…